The present invention relates to a oscillation type angular velocity sensor and in particular to an oscillation type angular velocity sensor in which an oscillation direction of an oscillator can be adjusted.
In a conventional sensor of this type, due to errors caused by the raw material, the physical properties and/or the shape of an oscillator, an existing exciting direction of the oscillator sometimes may deviate from a designed exciting direction thereof, resulting in an erroneous signal called a null voltage being mixed in a signal indicating an angular velocity of the oscillator and such an erroneous signal becomes one of several causes making the S/N rate of the sensor worse.
In order to cope with such a phenomena, methods for correcting the deflection or deviation of the excitation direction of the oscillator have been developed. One of these methods is to cut off a portion of the oscillator as disclosed in Japanese Patent Laid-open Print No. Hei6 (1994AD)-289043. Another is to add a bit of bonding agent or solder on the oscillator as disclosed in Japanese Patent Laid-open Print No. Hei4 (1992AD)-332814. However, in the aforementioned adjustment of mass distribution in the oscillator, cutting-off and adding-on with respect to the oscillator are established such that a very small quantity is cut off and added on the oscillator, respectively in a stepwise manner. Thus it takes a long time for finishing such an adjustment which results in poor yield. In addition, the foregoing methods cannot be established while the oscillator is being oscillated and cannot be applied in the automatic production of the sensors.